Molded plastics are frequently made of thermoplastic materials which are damaged by solvent attack. Polystyrene typifies such plastics. Being thermoplastic, it is easily molded into desired shape. However, the final product is still sensitive to organic solvents, and it is sometimes desired to improve its abrasion resistance or to apply a decorative overcoat. The solvent sensitivity of the molding makes it very difficult to coat the molding, especially when heat must be used to cure the coating to make it more resistant to solvent attack or to abrasion, or to render it better able to accept subsequent coatings which would damage the molding if it were unprotected.
Thermosetting coatings are commonly available, but these are either based on solvents which attack the molding which it is desired to protect, or they require temperatures of about 200.degree. F. or higher for cure, or both, and hence cannot be used to provide the protection which is desired. When most thermosettings are catalyzed with large amounts of catalyst to maximize the cure rate, this introduces water sensitivity and the cured coatings cannot withstand extreme exposure.